Grinding and drying apparatus



-June 14, 1927. J. E BELL 1,632,109

GRINDING AND DRYING APPARATUS Filed Jan.12. 1922 9 Sheets-Sheet l ig' R\ s@ *S v uw f June` 14, 1927. 1,632,109

J. E. BELL GRINDING AND DRYING APPARATUS Filed Jan. 12. 1922 9 Sheets-Sheet 2 3mm/nto@ jbd (1)100 329% @jf/toma# l June 14, 1927, 1,632,109

. J. E. BELL GRINDING AND DRYING APPARATUS Filed Jan. l2, 1922 9 Sheets-Sheet 5 5140114450@ Willms- Y /J '5 June 14,1927. 1,632,109

' J. E. BELL GRINDING AND DRYING APPARATUS Filed Jan.12. 1922 9 sheets-sheet 4 June-14,1927. A 1,632,109l

J. E. BELL GRINING AND DRYING APPARATUS Filed Jan. l2. 1922 9 Sheets-Sheet 5 June 14, 1927.

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/ J. E. BELL GRINDING AND D RYING APPARATUS Filed Jan. l2, 1922 9 Sheets-Sheet 7 Z. 55% GMO/:Mug

June 14, 1927. 1,632,109 J. E. BELL yGRINDINGr AND DRYING APPARATUS Filed Jan. l2, 1922 9 Sheets-Sheet 8 June 14. 1927. 1,632,109

J1 'E. BELL GRIN'DING AND DRYING APPARATUS Filed Jan. 12.V 1922 9 Sheets-Sheet nventoz 33MB SH01/neg WIM . Patented June 14; 1927.

UNITED STATES PATENT oFr-icE.

JOHN E. BELL, or Bnooxi-:YNNEW Yonx, AssIGNoR 'ro coinUsTIoN ENGINEERING conrouTIoN, .A conronaTIoN or'eNEw Yonx. l

GBINDING AND 'Dnvnm'nrana'rus animation mea January 12, 1922. seriai No. saam.

My invention relates to grindingand drying apparatus especially useful for preparing pulverized fuel such as coal that is to be burned in powdered form. vI aim to make both the crushing or grinding and the drying operations rapid, continuous, eilicient and economical, and to enable them to be carried on concurrently. I also aim to make the apparatus itself simple and com' pact, durable and rugged in service, and

relativelyinexpensive as regards both maintenance and initial cost. How these and other advantages can be realized through my invention will appear from my descrip-v ofthe apparatus, an Fig. 2l the discharge end.

Fig. 3 shows a transverse section .through the apparatus, taken as indicated by the line 3-3 in Fig. 1.

Fig. 4 is a plan view of the apparatus, on a smaller scale than Figs. 1 to 3, showing the connections for lsupply or circulation of a heating' (or cooling) medium. i

Fig. 5 is an end view from the left of Figs. 2 and 4 (on a larger scale than Fig. 4),`

with parts in front of a lane of section indicated by the line 5-5 1n Fig. 2 broken away and removed. l.

Figs. 6 and 7 together show a vertical axial section through another form of apparatiis embodying m showing the fuel inta e end of the appara-` tus, 4and Fig. 7 the discharge end. y

Figs. 8, 9 and 10 show transverse sections through the apparatus at various points, taken as indicated b vthe lines 8--8 and 9-9 in Fig. 6, and ythe line 10-10 in,

Fi r. 7. r

"{he apparatus shown in Figs. 1, 2 and 3 comprises a horizontal rotar casing. or shell comprehensively indicated y thel numeral 11, in which the fuel is ground, dried, heat- -be driven from any suitable invention,'-Fig. 6

ed or cooled, as required. At its ends,fthe` shell .or drum 11.*has hollow supporting, trunnions or journals 12, 13, winch are mounted to turn in Water-cooled journal boxes or bearings -14y 15. The shell may source by means of a gear 16 keyed fast on the end of the journal 12. Fuel is fed into the drum 1l at its rotatingjournal 12 as intake, through a stationary conduit sleeve 17 provided with a receiving hopper 18,` with the aid of a rotary feed screw 19. p The feed screw 19 may be driven from. any suitable source (preferably but not necessarily the same as that whencethe drum llitself is driven) by means of a pulley 2O keyed fast on the end `rof the screw shaft. Its rate of'revolu- 70 tion may preferably bear a suitable definite relation to that of the drum 11, according' to the conditions of operation existing from time to time. The fuel enterin' vthe drumv 11by the: journal 12 at the legt-hand end (Fig. 1) is fed through grinding devices in thedrum bythe impulsion of that fedV in after it, is crushed and ground to the desired degree of finenessb said devices, and is ultimately discharge by gravity 'from the drum through peripheral portage 22 at its right-hand end .(Fig. 2). .From Athe discharge orts 22, the fuel drops between external anges 23 oriv the drum 11 that rotate in circular openings in the lwalls of a re'- 85 ceivcr or casing structure annularly circumjacent the ports 22, as indicated at 24, and substantially seal with said walls. A dusttightjoint is formed. around the rotating flanges 23 lby stationary packings 25, 25 on the casing 24 that run in peripheral grooves in said flanges.

The progressive breaking up of. the fuel in grindingpermits progressive liberation of suchjmoisture as maybe present in it. In

order that full advantage may be taken of this favorable opportunity for. drying the fuel, I prefer to provide for passin a drying medium over or through the fuel Wiile lbeing ground, to absorb or'carry off the moisl ture,preferably ina direction the reverse of that in which the fuel travels, so thatthe driest air comes in contact with the driest fuel. 'As here shown, airfor lthis purpose enters .then drum 11 at lits right-hand end, `1015' through the upper portion of the casing 24 larger opening 30 in a frustro-conical dia,

p'hragm 31 at the inner side -of the portage 26 Vso that the -fuel cannot get into the air discharge.

Referring, now, to Fig. 3 as well as to Figs. 1 and 2, it will be seen that in the path of the fuel as it traverses the drum 11 are one or more (here a series of six) grinding devices, which inthe present instance are of a gravitational type, and counterparts of one another. As shown, each of these devices com rises a circular liner band or internal trac 33 at the periphery of the drum and a tire-like annular member 35 adapted toA roll uprighton said track, as the drum 11 revolves, under lateral guidance ofinward projecting lugs or vanes 36, 36 at either s1de of the track. As the tire 35 thus rolls under the influence of gravity, it always remains substantially at the low pointfof the track 33. The track' 33 should preferably be of very hard steel (such as manganese steel), and the tire 35 of ordinary tire steel such as used foi-the tires of railway wheels. Preferably, the internal crushing or surface of the track 33 is concave transversely, in the are of a circle, and the external crushing or grinding surface of the tire 35 is made correspondingly and concentrically convex,to the same radius of curvature.. Except at the center 37, the interior of the' tire 35 and the casing 11 are occluded by a transverse partition or web 38, extending inward from and across the inside of the tire. B 'keeping the fuel from passing freely an directly across the internal periphery of the tire 35, the diaphragm 38 causes it to accumulate to such a depth on the interior ofthe drum 11 that as it is car# riedup with the revolving drum (with some assistance .from the lugs 36) it is crowded and directed across the. internal track 33 and the periphery of the tire 35, through the gap that exists between them ever where above the low point of the track. wing to the continual feeding in of the fuel at 12, this condition obtains to the left of every track 33 and tire 35. The fuel progressively crushed under` the weight of the tires 35 is fed across the track 33 and the inner surface of the tire by the ressure of fresh fuel contiiually entering tween tire Aand track,- and in this manner, the fuel is fed across 4all the tracks in succession.

If the amount of fuel fed in exceeds the rinding capacity of a grinding device, the excess will accumulate to such an extent as to overflow the diaphragm 38 and pass the tire or tires 35 thus affected uncrushed. If the excess input of fuel is of sufficiently short duration, the fuel thus overflowing the left-hand diaphragms 38v will ultimately be crushed, nevertheless, by thev tires` 35 to the right.

The central openings 37 in the diaphragins,l

38 not only afford by-passage for excessive amounts of fuel from one track 33 to the next in the manner just described, but also adord passage for, drying air additional to that between tires and tracks above the fuel, and thus assure free 'passage 4of airin amounts fully adequate to absorb or carry the moisture from thefuel as it is progressively liberated. v

To aid in drying the fuel, I prefer to heat it ,during grinding, or to heat the drying air, or both., Without excluding preheating of the drying air, I have in the present instance provided for heating the shell 11 as a means of heating both the fuel and the air. For this purpose, the shell 11 is provided with a heatinjacket,- comprehensively indicated at 40, an provision is made for supplyin or circulating a heating medium even w ile shell and jacket 4are in motion. As shown in Figs. l'to 3, shell 11 and jacket 40 are consolidated, so to speak, in a unitary double walled sectional construction. Besides the intake section 41 (with the lshell end. 42, the flanges 27 with their interconnecting webs 43, and the diaphragm 31) and the discharge section 44 (of similar construction, though without any homologue for the dia hragm .31), the casing 11 comprises a set o super. posed counterpart hollow "annular sectlons 45, one to each ofthe (six) grinding devices 33, 35. When assembled, these sections 45 are secured together and to the end sec-` tions 41, 44 by bolts 46 taking through external flanges 47 at the abutting facesl of the sections. The inner wall of each section 45 has a shallow lgreovein whichthe annular track 33 is snugly seated, and securely held against lateral displacement by engagement with its shoulders. Each section "45 also comprises half of each of the guide lugs 36 `that separate adjacent tires 35, and are also adapted to prevent lateral displacement of the track 33. In order that the track 33 may be' absolutely integral and unbroken by joints (which would weaken it and tend to produce very rapid wear), it is preferable to make each annular section 45 in (six) double walled arc 'sections or segments 48 (Fig. 3) that can becoveniently assembled and secured together around the track. lAs shown,'.these hollow4 segments `48 intercommunicate, but are otherwise completely closed; they may be made tight with one Vanother by the usual means, such as interposed gaskets. It will be seen, therefore, that each high thermalcapaci-ty. For the purpose of supplying steam to the sectional jacket 40, the rotatlng hollow journal 13 at the righthand end of the shell 11 is extended beyond the bearing 1 5 through a stationary annular chamber 50 (Fig. 4) having a steam inlet 51. The journal 13 communicates with the chamber 50 through an annular series' of ports 52 in the journal,tight joints being insured by stuffing boxes 53 at either side 'of the chamber. At its other end, inside the bearing l5, the journal 13 is enlarged into a steam distribution. chamber 54 whence radiate (-see Figs. 4 and 5) conduit means Acomprising a number of pipes 55 by means of which the journal is connected to the j ackets in the several sections 45. As shown,

there are six of these pipes, each connected to one segment 48 of each annular jacket section 45.

For the purpose of relieving the sectional jacket 40 of water of condensation (and of air), a collection chamber 56 (Fig. 2) is provided in the journal 13 inside the distribution chamber 54. and from it adrain or draw-off pipe 57 is led through the midst of the axial steam'intake in the journal to a stationary elbow 58, provided with a stuifing box 59 to make a tight joint. The collection chamber 56 is connected to the jackets y45 by (six) pipes 60,-each of which is connected to one segment 48 of each ,annular jacket. As shown, the pipes 55 and 60 extend through the flanges 27 with a- `close fitand across the intervening space.

To insure flow of the water through the conduit means 60, 56, 57 each of them is first led helically around the lshell 11, clockwise (Figs. 3 and 5) from the furthest section 45 to the discharge section 44, and connected successively to the successive segments 48 of adjacent sections 45. Beyond the discharge section 44, each pipe 60 is led spirally inward clockwise to the collection chamber 56. Counterclockwise revolution of the shell 11,

therefore. will cause the water to flow by through the jacket and piping system willV result from the influence of gravity on lthe liquid in the` pipes 60 as the. drum 11 is rotated either clockwise or counterclockwise.

The apparatus shown in Figs. 6 to 10 differs from that just described in various particulars, the moreimportant 4of which may be briefly indicated. "In Figs.v 6 to 10, variousparts and features substantially like .corresponding featuresin Figs. 1 to' 5 have been markedA with the same reference numerals, as a means of avoiding merely.

repetitive description.

The casing,'shell, or drum'i71 is driven by an electric motor 72 whose shaft is coupled to a pinion 73 meshing with a large gear 74 bolted directly to the intake end 75 of the drum. At the discharge end76, the webs 77 interconnecting the flanges 26 extend radially instead of circumferentially. While the intake of fuel and of drying medium, (air) and the discharge of fuel are substantially the same as in Fi s.1 to. 3, the discharge of drying air is e ected somewhat differently,j`through a stationary chamber 78 that communicates with an'annular passage 79 around the fuel conduit 17 within the journal 12.

The crushin orgrinding devices in the shell 71 differ rom those of Figs. Lto 3 in several articulars. On each internal track are a p urality of tires, rolling one within another,-only the innermost havin the occluding diaphragms 38. -The tires are` here arranged in poly onal (triangular) sets at either side of eac `annular track, adjacent bar ends having overlapping feet 81 through which extend bolts 82 thatsecure them to the drum 71. The cornersy ofthe' guide bars are bevelled, so as to-enable them to coact with the edges of the tires in. crushing such material as may get between. The tracks 83 toward the fuel intake 12 (Figs. 1, 8 and 9) are not truly cir cular or integral, but polygonal faced, and composed of a multiplicity of Hat-faced,

arcuatebacked segments 84 secured against the interiorjof the shell -by bolts 85 whose heads 86 are counter-sunk and preferably `covered over with zinc, as shown at 87 in Fig. 8. The exteriors of the tires 88 and 89 are circular, as in Fig. 3;'but the interior or inner face of the intermediate tire 88- which serves as track to the smaller diaphragmed tire 89 within itis polygonal (though integral), like the track 83 itself.'

his polygonal track form is of advantage for the initial coarse crushing, since it allows the finer particles of fuel to cross the track with some degree of impunit so to speak, so that the weight of the tires is more or less concentrated on the larger pieces. The'tracks 90 (Figs. 2 and 10) toward the discharge end of the shell 71 are Athe fine particles ei'ectually, and the Iinteriors or inner faces of these .intermediate j tires 91 are likewise circular.

contrary, consists of a coupleof stout concentric metal cylinders or shells 92, 93 with heating jacket space 94 between them. At each of the bolts 82 and 85 a shouldered spacer 95 (preferably of cast steel is interposed between -the drums 92 an 93. Its reduced outer portion extends .through the outer shell 93 and takes the double nuts on the bolt. The edges of the spacer 95 maybe welded to the shell 92, and the edges of the reduced portionmay be welded to the shell 93,--for the sake of greater strength and fluid tightness. It will be seen that in this apparatus the shells 92, 93 are largely relied on to give the tracks 83 and 90 the required strength. The opposite ends of the shells 92, 93 are separated by annular lateral flanges 98 and 99 bolted to the end 7.5 and to the adjacent discharge flange 23, respectively, and are riveted to said flanges.

Steam for heating the shell 71 is supplied the jacket b the hollow journal 13, through a pipe 100 t at revolves in a stuing box 1n a stationary fittinglOll and thence extends inward to a three-way fitting 102 in the interior of lthis axial steam intake 13. From the fitting 102 radiate pipes 103 that extend across the fuel and air dischargey through hollow thickened portions 104 of the webs 77, and are connected to the adjacent end of the jacket 94. Water of condensation may be drawn off at each revolution by means of a balanced discharge valve 105 vbiased toward closing by a .helical compression spring 106, and actuated by a crank arm 107 pivoted to a bracket arm 108. on the valve. casing. The arm 107 carries a contact roller 109 which at each revolution of the Valve with the shell 71 may wipe against a cam track 110 mounted and adjustable in a bracket 111, so that it may be set in or out of the path of the roller,- or adjusted to regulate the length of time the valve 105 will be open according to the average amount of water to be got rid of. The blow-ofi' Valve 105 may discharge into a trough or funnel 112 on a drain pipe 113.

What I claim is:

1. A. continuous grinding and drying mill comprising a rotary casing with grinding means therein and peripheral portage at one end, and stationary casing means arranged annularly about said portage and substantially sealing with the rotary casing above and below at either sideof said portage, for discharge of ground material from the rotary casing below and passage of a rmedium for drying such material above.

2. A continuous grinding and drying mill comprising a rotary casing, with intake for material to be ground and with discharge for drying medium, one around the other, and also with discharge andintake means for such material and such medium, respectively, alfording peripheral portage for discharging: the material when ground; gravitational grinding means in said casing; and

r means for feeding material to be ground into said casing by the corresponding intake and through said grinding means to said discharge portage.

3. A continuous grinding and drying mill comprising a rotary casing, with hollow journal means for intake of material to be ground, and with peripheral .discharge means; grinding means in said casing; and

ymeans for discharge of drying medium from said casing around thel material entering at said journal means.

L1. A continuous grinding and drying mill comprising a rotary casing with hollow journal means for intake of material to be ground at one end and with peripheral discharge means at the other end, and with intake for drying medium; a series of internal tracks in said casing in the path of the material therethrough, and rotary tires adapted to roll- 0n said tracks as the casing revolves; means occluding the interiors of Said tires except at theiry centers, to prevent material from passing directly across their internal peripheries; and ymeans for discharge of drying medium from said casing around the material entering at said journal means.

5. A continuous grinding and drying mill i comprisinga rotary casing with grinding means therein; means for feeding material to be ground through said casing and its grinding means, means for passing drying medium through said casing to absorb moisture liberated from said material in grinding; and means for heatingthe material during grinding.

6. A continuous grinding and drying mill comprising a rotary casing with .a heating jacket and grinding means therein; means `for feeding material to be ground through said casing and its grinding means; means for passing drying medium through said casing to absorb moisture liberated fromsaid material in grinding; and means for passing a heating medium through saidjacket while revolving with said casing.

. 7. A continuous grinding and drying mill comprising a jacketed rotary casing with grinding means therein, hollow journal means for intake of material to be ground at one end and for passage of heating llOv mediumA for the jacket at the other end,-

peripheral portage at said latter mentioned end for discharge of ground material and passage of drying medium to absorb moisture liberated from the material in grinding, and means for passage of drying medium around the incoming material to be ground at the iirstLment-ioned end.

8. A continuous grinding and drying mill comprising a jacketed rotary casing with grinding means therein, hollow journal means for passage of materialv to be ground at one end and of heating medium for the jacket at the other end, means for'discharge of ground material lat said latter-mentioned end, and means for passing a dryinv medium through said casing and .its grin ing means counter to the travel of material being ground, to absorb moisture liberated from the latter.

9. A continuous grinding and drying mill comprising a rotary casing with intake for material to be ground and discharge for drying medium, one around the other, and discharge and intake means for such material and such medium, respectively affording peripheral'portage for the former; gravitational grinding meansin said casing; and

means for heating the material during grind- 111g. Y

10. A continuous grinding and drying mill comprising a jacketed rotary casing with hollow journal means for intake of lmaterial to be ground at one end and intake means for drying medium at the other end, and at the latter mentioned end peripheral discharge means for ground material and hollow journal means connected with the casing jacket for supplying heating medium thereto; a series of internal tracks in said casing in the path of the material therethrough; and rotary tires adapted to roll on said tracks as the casing revolves and crush the material traversingl them.

11. A continuous grinding and drying mill comprising a jacketed rotary casing having hollow journal means at one end and peripheral portage means at the other, and also having'discharge means for drying medium and hollow journal means at the aforementioned ends of said casing, respectively; grinding means in said casing; means for feeding material into said casing by one of the means first-mentioned and throu h said grinding means to the other of said Erst-mentioned means; and means for supplying heating medium to the casing jacket by the hollow journal means at the same end of the casing a's said peripheral yportage means.

12. A sectional grinding and drying mill comprising a set of superposed annular sections secured together aiid having internal tracks for the rolling of rotary tires as the mill revolves; asection secured to one end dium, withmeans of connection from said latter intake to said heating jackets.

13. A grinding and drying mill casing comprising end sections with intake and discharge means, and a jacketed intermediate portion comprising an internal grinding track and a double walled shell therearound, one of said last-mentioned parts being continuous and the' other in segmental sections.

14. A grinding mill casing comprising a plurality of superposed annular sections se-l cured together, including end sections having intake and discharge means, and intermediate sections having internal tracks for the rolling of rotary tires as the casing revolves and individual heating jackets for such sectionssurrounding said tracks.

15. A unitary casing section fora rolling tire grinding and drying milladapted to be secured to other casing sections at either side, and comprising 1n the one unitary structure an internal track for the tire, guide means for the tire.be side thev track, and a heating jacket'surrounding the track.

16. A vunitary casing section for a rolling tire grinding mill, comprising in the one unitary structure an internal track for the tire and a separate shell portion about said track carrying'means for preventing lateral displacement of the track and lateral guide means for the tire, and-also provided with means for securing the section in assembly with laterally 'adjacent casing sections. l

17. A grinding mill comprising a rotary casing with internal tracks, and rotary tires adapted to roll on said tracks as the casing revolves, the first'of such track and tire grinders in the path of the material having a polygonal faced member, so as to permit relatively ne particles to pass it freely, and the last comprising circular faced members for grinding such particles.

18. Av grinding mill'comprising a rotary casing with a polygonal surfaced internal track; and arotary tire adapted to roll o n said track as said casing revolves.

19. A grinding mill comprising a rotary casing with a polygonal surfaced internal track; and a circular rotary tire adapted to roll on said track as said casin revolves.

20. A grinding mill comprising a j acketed rotary casing with grinding means and with hollow journal means for intake of a medium circulating through the jacket, and means of connection between said journal and said jacket comprising a conduit extending helically around said casing from its jacket connection toward its journal connection, and spirally inward to said journal means.

21; A grinding mill comprising a jacketed t rotary casing with grinding means and with hollow journal meansy for intake of a me- -dium circulating through the jacket, and

means of connection between said journal andA said jacket comprising a conduit extending helically around said casinor from its jacket connection toward its 4journal connection.

22. A grinding mill comprising-a j acketed 'rotary casing with grinding means and with hollow journal means for intake of a medium circulating through `the jacket, and means of connection between said journal and said jacket comprising a conduit extending inward spirally between its jacket connection and its journal connection.

23. A grinding mill com rising a plurality of superposed indivi ually jacketed annular casing sections secured together,

with hollow journal means for intake of a. y

JOHN E. BELL. 

